#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = 1001001001;
const ll LINF = 1001002003004005006ll;
//const int mod = 1000000007;
//const int mod = 998244353;

int main()
{
  ll a, b, c;
  cin >> a >> b >> c;
  set<ll> st;
  if ((b+c)%a == 0 && a - b > 0) st.insert((b+c)/a);
  if (c%a == 0 && a - b <= 0) st.insert(c/a);
  if (st.size() == 0) cout << -1 << endl;
  else {
    for (ll i : st) cout << i << endl;
  }
  return 0;
}